/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

 var Class = require('../../utils/Class');
 var CONST = require('../const');
 var File = require('../File');
 var FileTypesManager = require('../FileTypesManager');
 var GetFastValue = require('../../utils/object/GetFastValue');
 var IsPlainObject = require('../../utils/object/IsPlainObject');
 
 /**
  * @classdesc
  * A single Scene Plugin Script File suitable for loading by the Loader.
  *
  * These are created when you use the Phaser.Loader.LoaderPlugin#scenePlugin method and are not typically created directly.
  *
  * For documentation about what all the arguments and configuration options mean please see Phaser.Loader.LoaderPlugin#scenePlugin.
  *
  * @class ScenePluginFile
  * @extends Phaser.Loader.File
  * @memberof Phaser.Loader.FileTypes
  * @constructor
  * @since 3.8.0
  *
  * @param {Phaser.Loader.LoaderPlugin} loader - A reference to the Loader that is responsible for this file.
  * @param {(string|Phaser.Types.Loader.FileTypes.ScenePluginFileConfig)} key - The key to use for this file, or a file configuration object.
  * @param {string} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.js`, i.e. if `key` was "alien" then the URL will be "alien.js".
  * @param {string} [systemKey] - If this plugin is to be added to Scene.Systems, this is the property key for it.
  * @param {string} [sceneKey] - If this plugin is to be added to the Scene, this is the property key for it.
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - Extra XHR Settings specifically for this file.
  */
 var ScenePluginFile = new Class({
 
     Extends: File,
 
     initialize:
 
     function ScenePluginFile (loader, key, url, systemKey, sceneKey, xhrSettings)
     {
         var extension = 'js';
 
         if (IsPlainObject(key))
         {
             var config = key;
 
             key = GetFastValue(config, 'key');
             url = GetFastValue(config, 'url');
             xhrSettings = GetFastValue(config, 'xhrSettings');
             extension = GetFastValue(config, 'extension', extension);
             systemKey = GetFastValue(config, 'systemKey');
             sceneKey = GetFastValue(config, 'sceneKey');
         }
 
         var fileConfig = {
             type: 'scenePlugin',
             cache: false,
             extension: extension,
             responseType: 'text',
             key: key,
             url: url,
             xhrSettings: xhrSettings,
             config: {
                 systemKey: systemKey,
                 sceneKey: sceneKey
             }
         };
 
         File.call(this, loader, fileConfig);
 
         // If the url variable refers to a class, add the plugin directly
         if (typeof url === 'function')
         {
             this.data = url;
 
             this.state = CONST.FILE_POPULATED;
         }
     },
 
     /**
      * Called automatically by Loader.nextFile.
      * This method controls what extra work this File does with its loaded data.
      *
      * @method Phaser.Loader.FileTypes.ScenePluginFile#onProcess
      * @since 3.8.0
      */
     onProcess: function ()
     {
         var pluginManager = this.loader.systems.plugins;
         var config = this.config;
 
         var key = this.key;
         var systemKey = GetFastValue(config, 'systemKey', key);
         var sceneKey = GetFastValue(config, 'sceneKey', key);
 
         if (this.state === CONST.FILE_POPULATED)
         {
             pluginManager.installScenePlugin(systemKey, this.data, sceneKey, this.loader.scene, true);
         }
         else
         {
             //  Plugin added via a js file
             this.state = CONST.FILE_PROCESSING;
 
             this.data = document.createElement('script');
             this.data.language = 'javascript';
             this.data.type = 'text/javascript';
             this.data.defer = false;
             this.data.text = this.xhrLoader.responseText;
 
             document.head.appendChild(this.data);
 
             pluginManager.installScenePlugin(systemKey, window[this.key], sceneKey, this.loader.scene, true);
         }
 
         this.onProcessComplete();
     }
 
 });
 
 /**
  * Adds a Scene Plugin Script file, or array of plugin files, to the current load queue.
  *
  * You can call this method from within your Scene's `preload`, along with any other files you wish to load:
  *
  * ```javascript
  * function preload ()
  * {
  *     this.load.scenePlugin('ModPlayer', 'plugins/ModPlayer.js', 'modPlayer', 'mods');
  * }
  * ```
  *
  * The file is **not** loaded right away. It is added to a queue ready to be loaded either when the loader starts,
  * or if it's already running, when the next free load slot becomes available. This happens automatically if you
  * are calling this from within the Scene's `preload` method, or a related callback. Because the file is queued
  * it means you cannot use the file immediately after calling this method, but must wait for the file to complete.
  * The typical flow for a Phaser Scene is that you load assets in the Scene's `preload` method and then when the
  * Scene's `create` method is called you are guaranteed that all of those assets are ready for use and have been
  * loaded.
  *
  * The key must be a unique String and not already in-use by another file in the Loader.
  *
  * Instead of passing arguments you can pass a configuration object, such as:
  *
  * ```javascript
  * this.load.scenePlugin({
  *     key: 'modplayer',
  *     url: 'plugins/ModPlayer.js'
  * });
  * ```
  *
  * See the documentation for `Phaser.Types.Loader.FileTypes.ScenePluginFileConfig` for more details.
  *
  * Once the file has finished loading it will automatically be converted into a script element
  * via `document.createElement('script')`. It will have its language set to JavaScript, `defer` set to
  * false and then the resulting element will be appended to `document.head`. Any code then in the
  * script will be executed. It will then be passed to the Phaser PluginCache.register method.
  *
  * The URL can be relative or absolute. If the URL is relative the `Loader.baseURL` and `Loader.path` values will be prepended to it.
  *
  * If the URL isn't specified the Loader will take the key and create a filename from that. For example if the key is "alien"
  * and no URL is given then the Loader will set the URL to be "alien.js". It will always add `.js` as the extension, although
  * this can be overridden if using an object instead of method arguments. If you do not desire this action then provide a URL.
  *
  * Note: The ability to load this type of file will only be available if the Script File type has been built into Phaser.
  * It is available in the default build but can be excluded from custom builds.
  *
  * @method Phaser.Loader.LoaderPlugin#scenePlugin
  * @fires Phaser.Loader.LoaderPlugin#ADD
  * @since 3.8.0
  *
  * @param {(string|Phaser.Types.Loader.FileTypes.ScenePluginFileConfig|Phaser.Types.Loader.FileTypes.ScenePluginFileConfig[])} key - The key to use for this file, or a file configuration object, or array of them.
  * @param {(string|function)} [url] - The absolute or relative URL to load this file from. If undefined or `null` it will be set to `<key>.js`, i.e. if `key` was "alien" then the URL will be "alien.js". Or, set to a plugin function.
  * @param {string} [systemKey] - If this plugin is to be added to Scene.Systems, this is the property key for it.
  * @param {string} [sceneKey] - If this plugin is to be added to the Scene, this is the property key for it.
  * @param {Phaser.Types.Loader.XHRSettingsObject} [xhrSettings] - An XHR Settings configuration object. Used in replacement of the Loaders default XHR Settings.
  *
  * @return {this} The Loader instance.
  */
 FileTypesManager.register('scenePlugin', function (key, url, systemKey, sceneKey, xhrSettings)
 {
     if (Array.isArray(key))
     {
         for (var i = 0; i < key.length; i++)
         {
             //  If it's an array it has to be an array of Objects, so we get everything out of the 'key' object
             this.addFile(new ScenePluginFile(this, key[i]));
         }
     }
     else
     {
         this.addFile(new ScenePluginFile(this, key, url, systemKey, sceneKey, xhrSettings));
     }
 
     return this;
 });
 
 module.exports = ScenePluginFile;
 